The National Renewable Energy Laboratory, with partners MIT-Comillas-IIT and Alstom Grid, develop combined distribution-transmission power grid models. Distribution models are created using a version of Comillas’ Reference Network Model (RNM), adapted to U.S. utilities, and based on real data from a broad range of utility partners. The models are complemented by the development of customizable scenarios that can be used for accurate algorithm comparisons. These scenarios take into account unknown factors that affect the grid like future power generation technologies, including distributed energy resources, such as residential solar and home energy storage, varying electrical load, disruptions due to weather events, solar and wind data, and repeatable contingency sequences.